aboutsummaryrefslogtreecommitdiffstats
path: root/fs/buffer.c
Commit message (Collapse)AuthorAge
* Fix race in create_empty_buffers() vs __set_page_dirty_buffers()Linus Torvalds2009-03-19
| | | | | | | | | | | | | | | Nick Piggin noticed this (very unlikely) race between setting a page dirty and creating the buffers for it - we need to hold the mapping private_lock until we've set the page dirty bit in order to make sure that create_empty_buffers() might not build up a set of buffers without the dirty bits set when the page is dirty. I doubt anybody has ever hit this race (and it didn't solve the issue Nick was looking at), but as Nick says: "Still, it does appear to solve a real race, which we should close." Acked-by: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2009-02-18
|\ | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: block: fix deadlock in blk_abort_queue() for drivers that readd to timeout list block: fix booting from partitioned md array block: revert part of 18ce3751ccd488c78d3827e9f6bf54e6322676fb cciss: PCI power management reset for kexec paride/pg.c: xs(): &&/|| confusion fs/bio: bio_alloc_bioset: pass right object ptr to mempool_free block: fix bad definition of BIO_RW_SYNC bsg: Fix sense buffer bug in SG_IO
| * block: revert part of 18ce3751ccd488c78d3827e9f6bf54e6322676fbJens Axboe2009-02-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The above commit added WRITE_SYNC and switched various places to using that for committing writes that will be waited upon immediately after submission. However, this causes a performance regression with AS and CFQ for ext3 at least, since sync_dirty_buffer() will submit some writes with WRITE_SYNC while ext3 has sumitted others dependent writes without the sync flag set. This causes excessive anticipation/idling in the IO scheduler because sync and async writes get interleaved, causing a big performance regression for the below test case (which is meant to simulate sqlite like behaviour). ---- test case ---- int main(int argc, char **argv) { int fdes, i; FILE *fp; struct timeval start; struct timeval end; struct timeval res; gettimeofday(&start, NULL); for (i=0; i<ROWS; i++) { fp = fopen("test_file", "a"); fprintf(fp, "Some Text Data\n"); fdes = fileno(fp); fsync(fdes); fclose(fp); } gettimeofday(&end, NULL); timersub(&end, &start, &res); fprintf(stdout, "time to write %d lines is %ld(msec)\n", ROWS, (res.tv_sec*1000000 + res.tv_usec)/1000); return 0; } ------------------- Thanks to Sean.White@APCC.com for tracking down this performance regression and providing a test case. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | mm: task dirty accounting fixNick Piggin2009-02-18
|/ | | | | | | | | | | | | | | | | | YAMAMOTO-san noticed that task_dirty_inc doesn't seem to be called properly for cases where set_page_dirty is not used to dirty a page (eg. mark_buffer_dirty). Additionally, there is some inconsistency about when task_dirty_inc is called. It is used for dirty balancing, however it even gets called for __set_page_dirty_no_writeback. So rather than increment it in a set_page_dirty wrapper, move it down to exactly where the dirty page accounting stats are incremented. Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp> Signed-off-by: Nick Piggin <npiggin@suse.de> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: Don't call attach_nobh_buffers() with an empty listDave Kleikamp2009-02-06
| | | | | | | | | | | | | | | | | | | | | | | | This is a modification of a patch by Bill Pemberton <wfp5p@virginia.edu> nobh_write_end() could call attach_nobh_buffers() with head == NULL. This would result in a trap when attach_nobh_buffers() attempted to access bh->b_this_page. This can be illustrated by running the writev01 testcase from LTP on jfs. This error was introduced by commit 5b41e74a "vfs: fix data leak in nobh_write_end()". That patch did not take into account that if PageMappedToDisk() is true upon entry to nobh_write_begin(), then no buffers will be allocated for the page. In that case, we won't have to worry about a failed write leaving unitialized data in the page. Of course, head != NULL implies !page_has_buffers(page), so no need to test both. Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Dmitri Monakhov <dmonakhov@openvz.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* [CVE-2009-0029] System call wrappers part 10Heiko Carstens2009-01-14
| | | | Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
* filesystem freeze: implement generic freeze featureTakashi Sato2009-01-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ioctls for the generic freeze feature are below. o Freeze the filesystem int ioctl(int fd, int FIFREEZE, arg) fd: The file descriptor of the mountpoint FIFREEZE: request code for the freeze arg: Ignored Return value: 0 if the operation succeeds. Otherwise, -1 o Unfreeze the filesystem int ioctl(int fd, int FITHAW, arg) fd: The file descriptor of the mountpoint FITHAW: request code for unfreeze arg: Ignored Return value: 0 if the operation succeeds. Otherwise, -1 Error number: If the filesystem has already been unfrozen, errno is set to EINVAL. [akpm@linux-foundation.org: fix CONFIG_BLOCK=n] Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com> Cc: <xfs-masters@oss.sgi.com> Cc: <linux-ext4@vger.kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* filesystem freeze: add error handling of write_super_lockfs/unlockfsTakashi Sato2009-01-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, ext3 in mainline Linux doesn't have the freeze feature which suspends write requests. So, we cannot take a backup which keeps the filesystem's consistency with the storage device's features (snapshot and replication) while it is mounted. In many case, a commercial filesystem (e.g. VxFS) has the freeze feature and it would be used to get the consistent backup. If Linux's standard filesystem ext3 has the freeze feature, we can do it without a commercial filesystem. So I have implemented the ioctls of the freeze feature. I think we can take the consistent backup with the following steps. 1. Freeze the filesystem with the freeze ioctl. 2. Separate the replication volume or create the snapshot with the storage device's feature. 3. Unfreeze the filesystem with the unfreeze ioctl. 4. Take the backup from the separated replication volume or the snapshot. This patch: VFS: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that they can return an error. Rename write_super_lockfs and unlockfs of the super block operation freeze_fs and unfreeze_fs to avoid a confusion. ext3, ext4, xfs, gfs2, jfs: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that write_super_lockfs returns an error if needed, and unlockfs always returns 0. reiserfs: Changed the type of write_super_lockfs and unlockfs from "void" to "int" so that they always return 0 (success) to keep a current behavior. Signed-off-by: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Masayuki Hamaguchi <m-hamaguchi@ys.jp.nec.com> Cc: <xfs-masters@oss.sgi.com> Cc: <linux-ext4@vger.kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Kleikamp <shaggy@austin.ibm.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block_write_begin(): remove useless gotoFranck Bui-Huu2009-01-06
| | | | | | Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: symlink write_begin allocation context fixNick Piggin2009-01-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the write_begin/write_end aops, page_symlink was broken because it could no longer pass a GFP_NOFS type mask into the point where the allocations happened. They are done in write_begin, which would always assume that the filesystem can be entered from reclaim. This bug could cause filesystem deadlocks. The funny thing with having a gfp_t mask there is that it doesn't really allow the caller to arbitrarily tinker with the context in which it can be called. It couldn't ever be GFP_ATOMIC, for example, because it needs to take the page lock. The only thing any callers care about is __GFP_FS anyway, so turn that into a single flag. Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on this flag in their write_begin function. Change __grab_cache_page to accept a nofs argument as well, to honour that flag (while we're there, change the name to grab_cache_page_write_begin which is more instructive and does away with random leading underscores). This is really a more flexible way to go in the end anyway -- if a filesystem happens to want any extra allocations aside from the pagecache ones in ints write_begin function, it may now use GFP_KERNEL (rather than GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a random example). [kosaki.motohiro@jp.fujitsu.com: fix ubifs] [kosaki.motohiro@jp.fujitsu.com: fix fuse] Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.28.x] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> [ Cleaned up the calling convention: just pass in the AOP flags untouched to the grab_cache_page_write_begin() function. That just simplifies everybody, and may even allow future expansion of the logic. - Linus ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: Supress Buffer I/O errors when SCSI REQ_QUIET flag setKeith Mannthey2008-12-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow the scsi request REQ_QUIET flag to be propagated to the buffer file system layer. The basic ideas is to pass the flag from the scsi request to the bio (block IO) and then to the buffer layer. The buffer layer can then suppress needless printks. This patch declutters the kernel log by removed the 40-50 (per lun) buffer io error messages seen during a boot in my multipath setup . It is a good chance any real errors will be missed in the "noise" it the logs without this patch. During boot I see blocks of messages like " __ratelimit: 211 callbacks suppressed Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242847 Buffer I/O error on device sdm, logical block 1 Buffer I/O error on device sdm, logical block 5242878 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242879 Buffer I/O error on device sdm, logical block 5242872 " in my logs. My disk environment is multipath fiber channel using the SCSI_DH_RDAC code and multipathd. This topology includes an "active" and "ghost" path for each lun. IO's to the "ghost" path will never complete and the SCSI layer, via the scsi device handler rdac code, quick returns the IOs to theses paths and sets the REQ_QUIET scsi flag to suppress the scsi layer messages. I am wanting to extend the QUIET behavior to include the buffer file system layer to deal with these errors as well. I have been running this patch for a while now on several boxes without issue. A few runs of bonnie++ show no noticeable difference in performance in my setup. Thanks for John Stultz for the quiet_error finalization. Submitted-by: Keith Mannthey <kmannth@us.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* udf: Fix BUG_ON() in destroy_inode()Jan Kara2008-11-27
| | | | | | | | | | | udf_clear_inode() can leave behind buffers on mapping's i_private list (when we truncated preallocation). Call invalidate_inode_buffers() so that the list is properly cleaned-up before we return from udf_clear_inode(). This is ugly and suggest that we should cleanup preallocation earlier than in clear_inode() but currently there's no such call available since drop_inode() is called under inode lock and thus is unusable for disk operations. Signed-off-by: Jan Kara <jack@suse.cz>
* fs: buffer lock use lock bitopsNick Piggin2008-10-20
| | | | | | | | | trylock_buffer and unlock_buffer open and close a critical section. Hence, we can use the lock bitops to get the desired memory ordering. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block: submit_bh() inadvertently discards barrier flag on a sync writeJens Axboe2008-08-27
| | | | | | | | Reported by Milan Broz <mbroz@redhat.com>, commit 18ce3751 inadvertently made submit_bh() discard the barrier bit for a WRITE_SYNC request. Fix that up. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* fs: rename buffer trylockNick Piggin2008-08-05
| | | | | | | | Like the page lock change, this also requires name change, so convert the raw test_and_set bitop to a trylock. Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/buffer.c: uninline __remove_assoc_queue()Thomas Petazzoni2008-07-30
| | | | | | | | | | | | | | | | | | Uninline the __remove_assoc_queue() function in fs/buffer.c, called at too many places and too long to really be inlined. Size results: text data bss dec hex filename 1134606 118840 212992 1466438 166046 vmlinux.old 1134303 118840 212992 1466135 165f17 vmlinux -303 0 0 -303 -12F +/- This patch is part of the Linux Tiny project and has been originally written by Matt Mackall <mpm@selenic.com>. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Cc: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: pagecache usage optimization for pagesize!=blocksizeHisashi Hifumi2008-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we read some part of a file through pagecache, if there is a pagecache of corresponding index but this page is not uptodate, read IO is issued and this page will be uptodate. I think this is good for pagesize == blocksize environment but there is room for improvement on pagesize != blocksize environment. Because in this case a page can have multiple buffers and even if a page is not uptodate, some buffers can be uptodate. So I suggest that when all buffers which correspond to a part of a file that we want to read are uptodate, use this pagecache and copy data from this pagecache to user buffer even if a page is not uptodate. This can reduce read IO and improve system throughput. I wrote a benchmark program and got result number with this program. This benchmark do: 1: mount and open a test file. 2: create a 512MB file. 3: close a file and umount. 4: mount and again open a test file. 5: pwrite randomly 300000 times on a test file. offset is aligned by IO size(1024bytes). 6: measure time of preading randomly 100000 times on a test file. The result was: 2.6.26 330 sec 2.6.26-patched 226 sec Arch:i386 Filesystem:ext3 Blocksize:1024 bytes Memory: 1GB On ext3/4, a file is written through buffer/block. So random read/write mixed workloads or random read after random write workloads are optimized with this patch under pagesize != blocksize environment. This test result showed this. The benchmark program is as follows: #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #include <time.h> #include <stdlib.h> #include <string.h> #include <sys/mount.h> #define LEN 1024 #define LOOP 1024*512 /* 512MB */ main(void) { unsigned long i, offset, filesize; int fd; char buf[LEN]; time_t t1, t2; if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) { perror("cannot mount\n"); exit(1); } memset(buf, 0, LEN); fd = open("/root/test1/testfile", O_CREAT|O_RDWR|O_TRUNC); if (fd < 0) { perror("cannot open file\n"); exit(1); } for (i = 0; i < LOOP; i++) write(fd, buf, LEN); close(fd); if (umount("/root/test1/") < 0) { perror("cannot umount\n"); exit(1); } if (mount("/dev/sda1", "/root/test1/", "ext3", 0, 0) < 0) { perror("cannot mount\n"); exit(1); } fd = open("/root/test1/testfile", O_RDWR); if (fd < 0) { perror("cannot open file\n"); exit(1); } filesize = LEN * LOOP; for (i = 0; i < 300000; i++){ offset = (random() % filesize) & (~(LEN - 1)); pwrite(fd, buf, LEN, offset); } printf("start test\n"); time(&t1); for (i = 0; i < 100000; i++){ offset = (random() % filesize) & (~(LEN - 1)); pread(fd, buf, LEN, offset); } time(&t2); printf("%ld sec\n", t2-t1); close(fd); if (umount("/root/test1/") < 0) { perror("cannot umount\n"); exit(1); } } Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jan Kara <jack@ucw.cz> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Use WARN() in fs/Arjan van de Ven2008-07-26
| | | | | | | | | Use WARN() instead of a printk+WARN_ON() pair; this way the message becomes part of the warning section for better reporting/collection. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* SL*B: drop kmem cache argument from constructorAlexey Dobriyan2008-07-26
| | | | | | | | | | | | | | | | | | | | | | | | Kmem cache passed to constructor is only needed for constructors that are themselves multiplexeres. Nobody uses this "feature", nor does anybody uses passed kmem cache in non-trivial way, so pass only pointer to object. Non-trivial places are: arch/powerpc/mm/init_64.c arch/powerpc/mm/hugetlbpage.c This is flag day, yes. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jon Tollefson <kniht@linux.vnet.ibm.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Matt Mackall <mpm@selenic.com> [akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c] [akpm@linux-foundation.org: fix mm/slab.c] [akpm@linux-foundation.org: fix ubifs] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: spinlock tree_lockNick Piggin2008-07-26
| | | | | | | | | | | | | | mapping->tree_lock has no read lockers. convert the lock from an rwlock to a spinlock. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Hugh Dickins <hugh@veritas.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Reviewed-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar2008-07-15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * on_each_cpu(): kill unused 'retry' parameterJens Axboe2008-06-26
| | | | | | | | | | | | | | | | | | It's not even passed on to smp_call_function() anymore, since that was removed. So kill it. Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | vfs: add hooks for ext4's delayed allocation supportAlex Tomas2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | Export mpage_bio_submit() and __mpage_writepage() for the benefit of ext4's delayed allocation support. Also change __block_write_full_page so that if buffers that have the BH_Delay flag set it will call get_block() to get the physical block allocated, just as in the !BH_Mapped case. Signed-off-by: Alex Tomas <alex@clusterfs.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | vfs: Move mark_inode_dirty() from under page lock in generic_write_end()Jan Kara2008-07-11
| | | | | | | | | | | | | | | | | | | | | | | | There's no need to call mark_inode_dirty() under page lock in generic_write_end(). It unnecessarily makes hold time of page lock longer and more importantly it forces locking order of page lock and transaction start for journaling filesystems. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
* | Properly notify block layer of sync writesJens Axboe2008-07-01
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | fsync_buffers_list() and sync_dirty_buffer() both issue async writes and then immediately wait on them. Conceptually, that makes them sync writes and we should treat them as such so that the IO schedulers can handle them appropriately. This patch fixes a write starvation issue that Lin Ming reported, where xx is stuck for more than 2 minutes because of a large number of synchronous IO in the system: INFO: task kjournald:20558 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kjournald D ffff810010820978 6712 20558 2 ffff81022ddb1d10 0000000000000046 ffff81022e7baa10 ffffffff803ba6f2 ffff81022ecd0000 ffff8101e6dc9160 ffff81022ecd0348 000000008048b6cb 0000000000000086 ffff81022c4e8d30 0000000000000000 ffffffff80247537 Call Trace: [<ffffffff803ba6f2>] kobject_get+0x12/0x17 [<ffffffff80247537>] getnstimeofday+0x2f/0x83 [<ffffffff8029c1ac>] sync_buffer+0x0/0x3f [<ffffffff8066d195>] io_schedule+0x5d/0x9f [<ffffffff8029c1e7>] sync_buffer+0x3b/0x3f [<ffffffff8066d3f0>] __wait_on_bit+0x40/0x6f [<ffffffff8029c1ac>] sync_buffer+0x0/0x3f [<ffffffff8066d48b>] out_of_line_wait_on_bit+0x6c/0x78 [<ffffffff80243909>] wake_bit_function+0x0/0x23 [<ffffffff8029e3ad>] sync_dirty_buffer+0x98/0xcb [<ffffffff8030056b>] journal_commit_transaction+0x97d/0xcb6 [<ffffffff8023a676>] lock_timer_base+0x26/0x4b [<ffffffff8030300a>] kjournald+0xc1/0x1fb [<ffffffff802438db>] autoremove_wake_function+0x0/0x2e [<ffffffff80302f49>] kjournald+0x0/0x1fb [<ffffffff802437bb>] kthread+0x47/0x74 [<ffffffff8022de51>] schedule_tail+0x28/0x5d [<ffffffff8020cac8>] child_rip+0xa/0x12 [<ffffffff80243774>] kthread+0x0/0x74 [<ffffffff8020cabe>] child_rip+0x0/0x12 Lin Ming confirms that this patch fixes the issue. I've run tests with it for the past week and no ill effects have been observed, so I'm proposing it for inclusion into 2.6.26. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* fs: replace remaining __FUNCTION__ occurrencesHarvey Harrison2008-04-30
| | | | | | | | __FUNCTION__ is gcc-specific, use __func__ Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* make fs/buffer.c:cont_expand_zero() staticAdrian Bunk2008-04-29
| | | | | | | | cont_expand_zero() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* remove generic_commit_write()Adrian Bunk2008-04-29
| | | | | | | | | Remove the obsolete and no longer used generic_commit_write(). Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add balance_dirty_pages_ratelimited() to cont_expand_zero()OGAWA Hirofumi2008-04-28
| | | | | | | | | | | | | | On the systems, ftruncate() which expand size for FAT became the cause of OOM. The cont_expand_zero() filled all memory with dirty pages, and since disk is very slow, limit of page scanning was exceeded, then it triggered OOM. This adds balance_dirty_pages_ratelimited() to avoid filling memory with dirty pages. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: filter based on a nodemask as well as a gfp_maskMel Gorman2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | The MPOL_BIND policy creates a zonelist that is used for allocations controlled by that mempolicy. As the per-node zonelist is already being filtered based on a zone id, this patch adds a version of __alloc_pages() that takes a nodemask for further filtering. This eliminates the need for MPOL_BIND to create a custom zonelist. A positive benefit of this is that allocations using MPOL_BIND now use the local node's distance-ordered zonelist instead of a custom node-id-ordered zonelist. I.e., pages will be allocated from the closest allowed node with available memory. [Lee.Schermerhorn@hp.com: Mempolicy: update stale documentation and comments] [Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask] [Lee.Schermerhorn@hp.com: Mempolicy: make dequeue_huge_page_vma() obey MPOL_BIND nodemask rework] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: have zonelist contains structs with both a zone pointer and zone_idxMel Gorman2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Filtering zonelists requires very frequent use of zone_idx(). This is costly as it involves a lookup of another structure and a substraction operation. As the zone_idx is often required, it should be quickly accessible. The node idx could also be stored here if it was found that accessing zone->node is significant which may be the case on workloads where nodemasks are heavily used. This patch introduces a struct zoneref to store a zone pointer and a zone index. The zonelist then consists of an array of these struct zonerefs which are looked up as necessary. Helpers are given for accessing the zone index as well as the node index. [kamezawa.hiroyu@jp.fujitsu.com: Suggested struct zoneref instead of embedding information in pointers] [hugh@veritas.com: mm-have-zonelist: fix memcg ooms] [hugh@veritas.com: just return do_try_to_free_pages] [hugh@veritas.com: do_try_to_free_pages gfp_mask redundant] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <clameter@sgi.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use two zonelist that are filtered by GFP maskMel Gorman2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | Currently a node has two sets of zonelists, one for each zone type in the system and a second set for GFP_THISNODE allocations. Based on the zones allowed by a gfp mask, one of these zonelists is selected. All of these zonelists consume memory and occupy cache lines. This patch replaces the multiple zonelists per-node with two zonelists. The first contains all populated zones in the system, ordered by distance, for fallback allocations when the target/preferred node has no free pages. The second contains all populated zones in the node suitable for GFP_THISNODE allocations. An iterator macro is introduced called for_each_zone_zonelist() that interates through each zone allowed by the GFP flags in the selected zonelist. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce node_zonelist() for accessing the zonelist for a GFP maskMel Gorman2008-04-28
| | | | | | | | | | | | | | | | | | Introduce a node_zonelist() helper function. It is used to lookup the appropriate zonelist given a node and a GFP mask. The patch on its own is a cleanup but it helps clarify parts of the two-zonelist-per-node patchset. If necessary, it can be merged with the next patch in this set without problems. Reviewed-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: use zonelists instead of zones when direct reclaiming pagesMel Gorman2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following patches replace multiple zonelists per node with two zonelists that are filtered based on the GFP flags. The patches as a set fix a bug with regard to the use of MPOL_BIND and ZONE_MOVABLE. With this patchset, the MPOL_BIND will apply to the two highest zones when the highest zone is ZONE_MOVABLE. This should be considered as an alternative fix for the MPOL_BIND+ZONE_MOVABLE in 2.6.23 to the previously discussed hack that filters only custom zonelists. The first patch cleans up an inconsistency where direct reclaim uses zonelist->zones where other places use zonelist. The second patch introduces a helper function node_zonelist() for looking up the appropriate zonelist for a GFP mask which simplifies patches later in the set. The third patch defines/remembers the "preferred zone" for numa statistics, as it is no longer always the first zone in a zonelist. The forth patch replaces multiple zonelists with two zonelists that are filtered. The two zonelists are due to the fact that the memoryless patchset introduces a second set of zonelists for __GFP_THISNODE. The fifth patch introduces helper macros for retrieving the zone and node indices of entries in a zonelist. The final patch introduces filtering of the zonelists based on a nodemask. Two zonelists exist per node, one for normal allocations and one for __GFP_THISNODE. Performance results varied depending on the machine configuration. In real workloads the gain/loss will depend on how much the userspace portion of the benchmark benefits from having more cache available due to reduced referencing of zonelists. These are the range of performance losses/gains when running against 2.6.24-rc4-mm1. The set and these machines are a mix of i386, x86_64 and ppc64 both NUMA and non-NUMA. loss to gain Total CPU time on Kernbench: -0.86% to 1.13% Elapsed time on Kernbench: -0.79% to 0.76% page_test from aim9: -4.37% to 0.79% brk_test from aim9: -0.71% to 4.07% fork_test from aim9: -1.84% to 4.60% exec_test from aim9: -0.71% to 1.08% This patch: The allocator deals with zonelists which indicate the order in which zones should be targeted for an allocation. Similarly, direct reclaim of pages iterates over an array of zones. For consistency, this patch converts direct reclaim to use a zonelist. No functionality is changed by this patch. This simplifies zonelist iterators in the next patch. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Remove set_migrateflags()Christoph Lameter2008-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | Migrate flags must be set on slab creation as agreed upon when the antifrag logic was reviewed. Otherwise some slabs of a slabcache will end up in the unmovable and others in the reclaimable section depending on which flag was active when a new slab page was allocated. This likely slid in somehow when antifrag was merged. Remove it. The buffer_heads are always allocated with __GFP_RECLAIMABLE because the SLAB_RECLAIM_ACCOUNT option is set. The set_migrateflags() never had any effect there. Radix tree allocations are not directly reclaimable but they are allocated with __GFP_RECLAIMABLE set on each allocation. We now set SLAB_RECLAIM_ACCOUNT on radix tree slab creation making sure that radix tree slabs are consistently placed in the reclaimable section. Radix tree slabs will also be accounted as such. There is then no user left of set_migratepages. So remove it. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Be more careful about marking buffers dirtyLinus Torvalds2008-04-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Mikulas Patocka noted that the optimization where we check if a buffer was already dirty (and we avoid re-dirtying it) was not really SMP-safe. Since the read of the old status was not synchronized with anything, an aggressive CPU re-ordering of memory accesses might have moved that read up to before the data was even written to the buffer, and another CPU that cleaned it again, causing the newly dirty state to never actually hit the disk. Admittedly this would probably never trigger in practice, but it's still wrong. Mikulas sent a patch that fixed the problem, but I dislike the subtlety of the whole optimization, so this is an alternate fix that is more explicit about the particular SMP ordering for the optimization, and separates out the speculative reads of the buffer state into its own conditional (and makes the memory barrier only happen if we are likely to actually hit the optimized case in the first place). I considered removing the optimization entirely, but Andrew argued for it's continued existence. I'm a push-over. Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: fix data leak in nobh_write_end()Dmitri Monakhov2008-03-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Current nobh_write_end() implementation ignore partial writes(copied < len) case if page was fully mapped and simply mark page as Uptodate, which is totally wrong because area [pos+copied, pos+len) wasn't updated explicitly in previous write_begin call. It simply contains garbage from pagecache and result in data leakage. #TEST_CASE_BEGIN: ~~~~~~~~~~~~~~~~ In fact issue triggered by classical testcase open("/mnt/test", O_RDWR|O_CREAT|O_TRUNC, 0666) = 3 ftruncate(3, 409600) = 0 writev(3, [{"a", 1}, {NULL, 4095}], 2) = 1 ##TESTCASE_SOURCE: ~~~~~~~~~~~~~~~~~ #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <sys/uio.h> #include <sys/mman.h> #include <errno.h> int main(int argc, char **argv) { int fd, ret; void* p; struct iovec iov[2]; fd = open(argv[1], O_RDWR|O_CREAT|O_TRUNC, 0666); ftruncate(fd, 409600); iov[0].iov_base="a"; iov[0].iov_len=1; iov[1].iov_base=NULL; iov[1].iov_len=4096; ret = writev(fd, iov, sizeof(iov)/sizeof(struct iovec)); printf("writev = %d, err = %d\n", ret, errno); return 0; } ##TESTCASE RESULT: ~~~~~~~~~~~~~~~~~~ [root@ts63 ~]# mount | grep mnt2 /dev/mapper/test on /mnt2 type ext2 (rw,nobh) [root@ts63 ~]# /tmp/writev /mnt2/test writev = 1, err = 0 [root@ts63 ~]# hexdump -C /mnt2/test 00000000 61 65 62 6f 6f 74 00 00 f0 b9 b4 59 3a 00 00 00 |aeboot.....Y:...| 00000010 20 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00 | .......!.......| 00000020 df df df df df df df df df df df df df df df df |................| 00000030 3a 00 00 00 2a 00 00 00 21 00 00 00 00 00 00 00 |:...*...!.......| 00000040 60 c0 8c 00 00 00 00 00 40 4a 8d 00 00 00 00 00 |`.......@J......| 00000050 00 00 00 00 00 00 00 00 41 00 00 00 00 00 00 00 |........A.......| 00000060 74 69 6d 65 20 64 64 20 69 66 3d 2f 64 65 76 2f |time dd if=/dev/| 00000070 6c 6f 6f 70 30 20 20 6f 66 3d 2f 64 65 76 2f 6e |loop0 of=/dev/n| skip.. 00000f50 00 00 00 00 00 00 00 00 31 00 00 00 00 00 00 00 |........1.......| 00000f60 6d 6b 66 73 2e 65 78 74 33 20 2f 64 65 76 2f 76 |mkfs.ext3 /dev/v| 00000f70 7a 76 67 2f 74 65 73 74 20 2d 62 34 30 39 36 00 |zvg/test -b4096.| 00000f80 a0 fe 8c 00 00 00 00 00 21 00 00 00 00 00 00 00 |........!.......| 00000f90 23 31 32 30 35 39 35 30 34 30 34 00 3a 00 00 00 |#1205950404.:...| 00000fa0 20 00 8d 00 00 00 00 00 21 00 00 00 00 00 00 00 | .......!.......| 00000fb0 d0 cf 8c 00 00 00 00 00 10 d0 8c 00 00 00 00 00 |................| 00000fc0 00 00 00 00 00 00 00 00 41 00 00 00 00 00 00 00 |........A.......| 00000fd0 6d 6f 75 6e 74 20 2f 64 65 76 2f 76 7a 76 67 2f |mount /dev/vzvg/| 00000fe0 74 65 73 74 20 20 2f 76 7a 20 2d 6f 20 64 61 74 |test /vz -o dat| 00000ff0 61 3d 77 72 69 74 65 62 61 63 6b 00 00 00 00 00 |a=writeback.....| 00001000 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................| As you can see file's page contains garbage from pagecache instead of zeros. #TEST_CASE_END Attached patch: - Add sanity check BUG_ON in order to prevent incorrect usage by caller, This is function invariant because page can has buffers and in no zero *fadata pointer at the same time. - Always attach buffers to page is it is partial write case. - Always switch back to generic_write_end if page has buffers. This is reasonable because if page already has buffer then generic_write_begin was called previously. Signed-off-by: Dmitri Monakhov <dmonakhov@openvz.org> Reviewed-by: Nick Piggin <npiggin@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: fix kernel-doc notation warningsRandy Dunlap2008-03-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix kernel-doc notation warnings in fs/. Warning(mmotm-2008-0314-1449//fs/super.c:560): missing initial short description on line: * mark_files_ro Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/locks.c:1277): missing initial short description on line: * lease_get_mtime Warning(mmotm-2008-0314-1449//fs/namei.c:1368): missing initial short description on line: * lookup_one_len: filesystem helper to lookup single pathname component Warning(mmotm-2008-0314-1449//fs/buffer.c:3221): missing initial short description on line: * bh_uptodate_or_lock: Test whether the buffer is uptodate Warning(mmotm-2008-0314-1449//fs/buffer.c:3240): missing initial short description on line: * bh_submit_read: Submit a locked buffer for reading Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:30): missing initial short description on line: * writeback_acquire: attempt to get exclusive writeback access to a device Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:47): missing initial short description on line: * writeback_in_progress: determine whether there is writeback in progress Warning(mmotm-2008-0314-1449//fs/fs-writeback.c:58): missing initial short description on line: * writeback_release: relinquish exclusive writeback access against a device. Warning(mmotm-2008-0314-1449//include/linux/jbd.h:351): contents before sections Warning(mmotm-2008-0314-1449//include/linux/jbd.h:561): contents before sections Warning(mmotm-2008-0314-1449//fs/jbd/transaction.c:1935): missing initial short description on line: * void journal_invalidatepage() Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* vfs: fix NULL pointer dereference in fsync_buffers_list()Jan Kara2008-03-04
| | | | | | | | | | | Fix NULL pointer dereference in fsync_buffers_list() introduced by recent fix of races in private_list handling. Since bh->b_assoc_map has been cleared in __remove_assoc_queue() we should really use original value stored in the 'mapping' variable. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* docbook: fix filesystems.tmpl source filesRandy Dunlap2008-03-03
| | | | | | | | Fix docbook problems in filesystems.tmpl. These cause the generated docbook to be incorrect. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* buffer_head: fix private_list handlingJan Kara2008-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two possible races in handling of private_list in buffer cache. 1) When fsync_buffers_list() processes a private_list, it clears b_assoc_mapping and moves buffer to its private list. Now drop_buffers() comes, sees a buffer is on list so it calls __remove_assoc_queue() which complains about b_assoc_mapping being cleared (as it cannot propagate possible IO error). This race has been actually observed in the wild. 2) When fsync_buffers_list() processes a private_list, mark_buffer_dirty_inode() can be called on bh which is already on the private list of fsync_buffers_list(). As buffer is on some list (note that the check is performed without private_lock), it is not readded to the mapping's private_list and after fsync_buffers_list() finishes, we have a dirty buffer which should be on private_list but it isn't. This race has not been reported, probably because most (but not all) callers of mark_buffer_dirty_inode() hold i_mutex and thus are serialized with fsync(). Fix these issues by not clearing b_assoc_map when fsync_buffers_list() moves buffer to a dedicated list and by reinserting buffer in private_list when it is found dirty after we have submitted buffer for IO. We also change the tests whether a buffer is on a private list from !list_empty(&bh->b_assoc_buffers) to bh->b_assoc_map so that they are single word reads and hence lockless checks are safe. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: remove fastcall, it is always emptyHarvey Harrison2008-02-08
| | | | | | | [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* rewrite rdNick Piggin2008-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a rewrite of the ramdisk block device driver. The old one is really difficult because it effectively implements a block device which serves data out of its own buffer cache. It relies on the dirty bit being set, to pin its backing store in cache, however there are non trivial paths which can clear the dirty bit (eg. try_to_free_buffers()), which had recently lead to data corruption. And in general it is completely wrong for a block device driver to do this. The new one is more like a regular block device driver. It has no idea about vm/vfs stuff. It's backing store is similar to the buffer cache (a simple radix-tree of pages), but it doesn't know anything about page cache (the pages in the radix tree are not pagecache pages). There is one slight downside -- direct block device access and filesystem metadata access goes through an extra copy and gets stored in RAM twice. However, this downside is only slight, because the real buffercache of the device is now reclaimable (because we're not playing crazy games with it), so under memory intensive situations, footprint should effectively be the same -- maybe even a slight advantage to the new driver because it can also reclaim buffer heads. The fact that it now goes through all the regular vm/fs paths makes it much more useful for testing, too. text data bss dec hex filename 2837 849 384 4070 fe6 drivers/block/rd.o 3528 371 12 3911 f47 drivers/block/brd.o Text is larger, but data and bss are smaller, making total size smaller. A few other nice things about it: - Similar structure and layout to the new loop device handlinag. - Dynamic ramdisk creation. - Runtime flexible buffer head size (because it is no longer part of the ramdisk code). - Boot / load time flexible ramdisk size, which could easily be extended to a per-ramdisk runtime changeable size (eg. with an ioctl). - Can use highmem for the backing store. [akpm@linux-foundation.org: fix build] [byron.bbradley@gmail.com: make rd_size non-static] Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Byron Bradley <byron.bbradley@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* bufferhead: revert constructor removalChristoph Lameter2008-02-05
| | | | | | | | | | | | | | | | | The constructor for buffer_head slabs was removed recently. We need the constructor back in slab defrag in order to insure that slab objects always have a definite state even before we allocated them. I think we mistakenly merged the removal of the constuctor into a cleanup patch. You (ie: akpm) had a test that showed that the removal of the constructor led to a small regression. The prior state makes things easier for slab defrag. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Pagecache zeroing: zero_user_segment, zero_user_segments and zero_userChristoph Lameter2008-02-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simplify page cache zeroing of segments of pages through 3 functions zero_user_segments(page, start1, end1, start2, end2) Zeros two segments of the page. It takes the position where to start and end the zeroing which avoids length calculations and makes code clearer. zero_user_segment(page, start, end) Same for a single segment. zero_user(page, start, length) Length variant for the case where we know the length. We remove the zero_user_page macro. Issues: 1. Its a macro. Inline functions are preferable. 2. The KM_USER0 macro is only defined for HIGHMEM. Having to treat this special case everywhere makes the code needlessly complex. The parameter for zeroing is always KM_USER0 except in one single case that we open code. Avoiding KM_USER0 makes a lot of code not having to be dealing with the special casing for HIGHMEM anymore. Dealing with kmap is only necessary for HIGHMEM configurations. In those configurations we use KM_USER0 like we do for a series of other functions defined in highmem.h. Since KM_USER0 is depends on HIGHMEM the existing zero_user_page function could not be a macro. zero_user_* functions introduced here can be be inline because that constant is not used when these functions are called. Also extract the flushing of the caches to be outside of the kmap. [akpm@linux-foundation.org: fix nfs and ntfs build] [akpm@linux-foundation.org: fix ntfs build some more] Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: <linux-ext4@vger.kernel.org> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Anton Altaparmakov <aia21@cantab.net> Cc: Mark Fasheh <mark.fasheh@oracle.com> Cc: David Chinner <dgc@sgi.com> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Cc: Steven French <sfrench@us.ibm.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Add buffer head related helper functionsAneesh Kumar K.V2008-01-28
| | | | | | | Add buffer head related helper function bh_uptodate_or_lock and bh_submit_read which can be used by file system Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
* nobh: nobh_write_end fixNick Piggin2007-10-21
| | | | | | | | | | | | | | | This path mustn't have been tested :( I did attempt to exercise it by injecting failures here, but I suspect PageMappedToDisk may have been getting in the way. Will need more of a look, although I think nobh mode is OK for an -rc1 (it shouldn't eat anyone's data). Commit 03158cd7eb3374843de68421142ca5900df845d9 ("fs: restore nobh") introcduced a NULL deref. Spotted by the Coverity checker. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Badari Pulavarty <pbadari@us.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* writeback: remove pages_skipped accounting in __block_write_full_page()Fengguang Wu2007-10-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Miklos Szeredi <miklos@szeredi.hu> and me identified a writeback bug: > The following strange behavior can be observed: > > 1. large file is written > 2. after 30 seconds, nr_dirty goes down by 1024 > 3. then for some time (< 30 sec) nothing happens (disk idle) > 4. then nr_dirty again goes down by 1024 > 5. repeat from 3. until whole file is written > > So basically a 4Mbyte chunk of the file is written every 30 seconds. > I'm quite sure this is not the intended behavior. It can be produced by the following test scheme: # cat bin/test-writeback.sh grep nr_dirty /proc/vmstat echo 1 > /proc/sys/fs/inode_debug dd if=/dev/zero of=/var/x bs=1K count=204800& while true; do grep nr_dirty /proc/vmstat; sleep 1; done # bin/test-writeback.sh nr_dirty 19207 nr_dirty 19207 nr_dirty 30924 204800+0 records in 204800+0 records out 209715200 bytes (210 MB) copied, 1.58363 seconds, 132 MB/s nr_dirty 47150 nr_dirty 47141 nr_dirty 47142 nr_dirty 47142 nr_dirty 47142 nr_dirty 47142 nr_dirty 47205 nr_dirty 47214 nr_dirty 47214 nr_dirty 47214 nr_dirty 47214 nr_dirty 47214 nr_dirty 47215 nr_dirty 47216 nr_dirty 47216 nr_dirty 47216 nr_dirty 47154 nr_dirty 47143 nr_dirty 47143 nr_dirty 47143 nr_dirty 47143 nr_dirty 47143 nr_dirty 47142 nr_dirty 47142 nr_dirty 47142 nr_dirty 47142 nr_dirty 47134 nr_dirty 47134 nr_dirty 47135 nr_dirty 47135 nr_dirty 47135 nr_dirty 46097 <== -1038 nr_dirty 46098 nr_dirty 46098 nr_dirty 46098 [...] nr_dirty 46091 nr_dirty 46092 nr_dirty 46092 nr_dirty 45069 <== -1023 nr_dirty 45056 nr_dirty 45056 nr_dirty 45056 [...] nr_dirty 37822 nr_dirty 36799 <== -1023 [...] nr_dirty 36781 nr_dirty 35758 <== -1023 [...] nr_dirty 34708 nr_dirty 33672 <== -1024 [...] nr_dirty 33692 nr_dirty 32669 <== -1023 % ls -li /var/x 847824 -rw-r--r-- 1 root root 200M 2007-08-12 04:12 /var/x % dmesg|grep 847824 # generated by a debug printk [ 529.263184] redirtied inode 847824 line 548 [ 564.250872] redirtied inode 847824 line 548 [ 594.272797] redirtied inode 847824 line 548 [ 629.231330] redirtied inode 847824 line 548 [ 659.224674] redirtied inode 847824 line 548 [ 689.219890] redirtied inode 847824 line 548 [ 724.226655] redirtied inode 847824 line 548 [ 759.198568] redirtied inode 847824 line 548 # line 548 in fs/fs-writeback.c: 543 if (wbc->pages_skipped != pages_skipped) { 544 /* 545 * writeback is not making progress due to locked 546 * buffers. Skip this inode for now. 547 */ 548 redirty_tail(inode); 549 } More debug efforts show that __block_write_full_page() never has the chance to call submit_bh() for that big dirty file: the buffer head is *clean*. So basicly no page io is issued by __block_write_full_page(), hence pages_skipped goes up. Also the comment in generic_sync_sb_inodes(): 544 /* 545 * writeback is not making progress due to locked 546 * buffers. Skip this inode for now. 547 */ and the comment in __block_write_full_page(): 1713 /* 1714 * The page was marked dirty, but the buffers were 1715 * clean. Someone wrote them back by hand with 1716 * ll_rw_block/submit_bh. A rare case. 1717 */ do not quite agree with each other. The page writeback should be skipped for 'locked buffer', but here it is 'clean buffer'! This patch fixes this bug. Though I'm not sure why __block_write_full_page() is called only to do nothing and who actually issued the writeback for us. This is the two possible new behaviors after the patch: 1) pretty nice: wait 30s and write ALL:) 2) not so good: - during the dd: ~16M - after 30s: ~4M - after 5s: ~4M - after 5s: ~176M The next patch will fix case (2). Cc: David Chinner <dgc@sgi.com> Cc: Ken Chen <kenchen@google.com> Signed-off-by: Fengguang Wu <wfg@mail.ustc.edu.cn> Signed-off-by: David Chinner <dgc@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: count reclaimable pages per BDIPeter Zijlstra2007-10-17
| | | | | | | | Count per BDI reclaimable pages; nr_reclaimable = nr_dirty + nr_unstable. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Group short-lived and reclaimable kernel allocationsMel Gorman2007-10-16
| | | | | | | | | | | | | | | | | | This patch marks a number of allocations that are either short-lived such as network buffers or are reclaimable such as inode allocations. When something like updatedb is called, long-lived and unmovable kernel allocations tend to be spread throughout the address space which increases fragmentation. This patch groups these allocations together as much as possible by adding a new MIGRATE_TYPE. The MIGRATE_RECLAIMABLE type is for allocations that can be reclaimed on demand, but not moved. i.e. they can be migrated by deleting them and re-reading the information from elsewhere. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-23 18:14:25 -0500